A wide variety of research which is based upon the unique capacities of fluorescence activated cell sorting is proposed. Funds for the purchase of a fluorescence-activated cell sorter to serve the research needs of NIH-grantees at the University of Illinois are sought. The fluorescence-activated cell sorter will be the core instrument in a cell sorting facility that will be housed within the School of Life Sciences, centrally located for the users. Since a fluorescence-activated cell sorter is presently not available at this University, this instrument will meet a need that has grown to critical proportions among NIH-supported researchers in many areas of cell biology. It will enable important research endeavors to be undertaken that will complement and expand upon current research activities. The scope of the research projects utilizing fluorescence-activated cell sorting methodology includes work in the areas of: receptors and hormone action, neurobiology, gene regulation, virology, cell cycle analysis, mitogenesis, malignant transformation, immunology, muscle development, and cell and organelle differentiation. The instrument will be employed in research projects of the following types: studies on estrogen receptors and hormone-responsiveness of human breast cancer and uterine cells; identification of the angiotensin II-receptor complex and its fate in isolated neurons; studies of maturation of the immune response; isolation and analysis of metabolic, developmental and receptor mutants; isolation of mutant cells resistant to viral oncogenesis and to growth factor-stimulated mitogenesis; immunochemical analysis of muscle development and cell lineages; studies on gene regulation in mutant cells defective in various aspects of the hormone response pathway; isolation of variant cells which exhibit altered levels and regulation of enzymes (such as HMG-CoA reductase); and preparation of hybridomas and analyses of their respective monoclonal antibodies. Because this would be the first fluorescence-activated cell sorter available to NIH-supported biomedical researchers on this campus, its impact would be enormous. It would enable the numerous NIH-supported laboratories to initiate new and important directions in their present research that would not otherwise be possible.